A well known method of removing insulation from wire or cable is to heat, and thereby partially melt, the insulation at a point on the wire near the area of insulation to be removed. This heating weakens the insulation and permits the insulation to be easily gripped and stripped from the wire or cable core without crimping, gouging or deforming the core, as commonly occurs with mechanical wire stripping. As can be readily appreciated, the temperature required to melt the insulation to permit stripping the insulation varies with insulator type and thickness. It is therefore desirable that a thermal stripping device be capable of operating at various temperatures. As can be further appreciated, a single-temperature stripping device may be adequate for some applications, but inadequate for others. For example, a device designed with a single, relatively low stripping element operating temperature for stripping relatively thin insulation, or insulation having a low melting point, may be inadequate for stripping thicker insulation, or insulation having a relatively high melting point. Conversely, a thermal wire stripper designed with a single, relatively high operating temperature for stripping insulation requiring high stripping temperatures will unnecessarily dissipate excess energy when used to strip thinner insulator material and may char the insulation. Indeed, it may even melt the wire itself. For these reasons, it is desirable that thermal wire stripping devices be designed to operate with variable stripping element temperatures.
To satisfy this requirement, many prior thermal stripping devices have been designed to permit heating the stripping elements to more than one operating temperature. A majority of these devices, however, have typically required the use of an alternating current power supply to heat the stripping elements. This power requirement has tended to make existing devices somewhat cumbersome to use, because a power cable from the alternating current power source must be attached to the device to energize it. This can be burdensome and, consequently, alternating current power stripping devices are not easily used in relatively inaccessible locations or in locations which are remote from an alternating current power supply.
To ameliorate the portability and accessibility problems normally associated with alternating current power, as noted above, direct current batteries have sometimes been used as power supplies for thermal stripping devices The single voltage output of direct current batteries, however, has limited the operation of these devices to a single temperature.
As can be appreciated from the foregoing discussion, it would be desirable to provide a thermal wire stripper which is powered by a relatively compact, portable direct current battery, yet which still permits the use of a wide range of stripping element temperatures. In view of the above, it is an object of the present invention to provide a thermal wire stripper which may be used to strip insulation of various types and thicknesses from wire or cable. It is a further object of the present invention to provide a thermal wire stripper which will accomplish the above for a wide range of insulation thicknesses and types without dissipating excess energy. Another object of the present invention is to provide a thermal wire stripper which is portable, yet capable of generating sufficient heat to strip insulation having a relatively high melting point. Still another object of the present invention is to provide a thermal wire stripper which is simple to use, easy to manufacture and relatively cost-effective.